damp plaster

[lami]

what is the best fix
had water ingress at chimney stack for some time , now fixed
put heater at it for a couple of days
plaster around top of breast is still wet about 2sqm
tried decorating but it came through
should i put a heater near it for a few days or
strip and replaster

 

[Softus]

Hack off and replaster. And if you feel like stripping then by all means do so

 

[pickles]

what is the best fix
had water ingress at chimney stack for some time , now fixed
put heater at it for a couple of days
plaster around top of breast is still wet about 2sqm
tried decorating but it came through
should i put a heater near it for a few days or
strip and replaster

Try running a dehumidifier in there for a few days, even a week. You can hire them easily

 

[rayal]

I agree with Softus (hack off and replaster)..........

The water ingress from the chimney stack carries with it soluble salts & soot deposits, albeit minute.........this has the effect of breaking down the surface plaster and at the same time absorbing moisture from the surrounding atmosphere. The situation is aggravated by warm air coming into contact with the damp wall surface, condensation and being absorbed into the wall plaster.

A secondary / primary source of damp appearing on the breast and surrounding ceiling area can be caused by warm air rising from within the property and condensating on the inside of the chimney.

A dehumidifier will help in the short term but it will not cure the problem....

When replastering use a 4:1 sand cement mix with a waterproofer / salt inhibiter in the gauging water and a skim plaster finish......

 

[noseall]

i agree with rayal, not all damp problems with chimney breasts are what they appear to be. sometimes the problem lies within the brickwork itself, whereby the bricks become saturated with deposits from whatever has been burned on the fire below, and eventually eek out onto the plaster. to remedy this you would need to re-plaster using s.b.r. solution and cement, all is explained on the bottle.